Fuel systems on board vehicles of various types generally comprise a tank for storing fuel, and this tank generally comprises at least one internal accessory. One particular case of such accessories is that of noise reduction baffles, the purpose of which is to absorb the noise (“slosh” noise) associated with the waves which may be generated inside the tank when the vehicle accelerates rapidly, brakes, turns, etc. Such baffles are also known as “anti-slosh baffles” in the automotive field.
Generally, these baffles are fixed into the tank after its manufacture by inserting it through an opening in its wall, for instance the one through which the pumping module is inserted and fixed inside the tank, and which is afterwards closed tightly by a flange. The problem is that generally, the baffle has a size which is bigger than the one of the opening and/or is too long to be inserted through said hole.
To solve that problem, so called “retractable baffles” have been developed. One specific kind of such baffles is the one described in U.S. Pat. No. 6,408,979 and US 2003/0015537 and which comprises 2 parts: a lower carrier and an upper sliding part which can slide relatively to the carrier thanks to compression springs mounted on retainers formed on the lower wall of the carrier and extending upwardly. To insert the baffle into the tank, these springs are compressed (reducing the size of the assembly) and they are relieved once the baffle is in place so has to increase its size substantially to the tank height. To put and keep the baffle in place, retainer bumps or flanges are molded in the tank lower and upper wall.
However, owed to the very telescopic nature of the baffle assembly, it may happen in some circumstances (for instance during manipulations of the empty fuel tank before it is fixed inside the vehicle; in the case of choc, rapid movement with a substantial amount inside the tank, deformations due to internal pressure variations or aging etc. . . . ) that these baffles start to slide and even, come out of their flanges.
Besides, the geometry and size of these flanges is such that they reduce the inner volume of the tank and hence, its available capacity.
Another problem with the baffles described in these US titles is that, especially in the case where the baffle does not occupy the entire section of the fuel tank (as for instance depicted in FIG. 1 of U.S. Pat. No. '537), these baffles may translate inside their flanges and hence, damage the tank wall.
Finally, with the shape of the flanges illustrated in these documents, it is not easy for the operator who fixes the baffle(s) inside the tank to be sure that the baffle is correctly in place.